Empirical analysis of hourly rainfall data in Sicily from 2002 to 2023

Rainfall constitutes an important climatic variable as its lack can lead to severe droughts while its excess can trigger catastrophic events. The Mediterranean basin is one of the European regions most affected by climate change’s effects and Sicily island, for its location in the middle of the Mediterranean sea, represents a very interesting place to study climatic variables. During the last decade, Sicily displayed unusual rainfall behavior and unexpected extreme events. In this paper, we depict how seasonal rainfall characteristics and trends changed since the beginning of twenty-first century. Using an empirical approach, we are able to confirm with a higher resolution previous results obtained through less granular data and detect the emergence of new anomalous behaviors. From our study we see that, after the heavy summer drought during 2009–2012, all seasons recorded a sudden volume variation: increasing during autumn–summer and decreasing in winter–spring. This coupled behavior emerges as an anomaly for the period 2013–2023: the similarity between summer–autumn and winter–spring highlights the passage from a 4 to a 2 season-like cycle,with the occurrence of severe droughts and frequent flash floods. The present contribution adds further evidence that a deep change is occurring and that new strategies for managing risks and resources are urgently needed to reduce human and economic losses. Graphic abstract